<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>3_回调ref中回调执行次数的问题</title>
</head>
<body>
  <!-- 准备好一个"容器" -->
  <div id="test1"></div>

  <!-- 引入React核心库 -->
  <script type="text/javascript" src="../js/react.development.js"></script>
  <!-- 引入react-dom，用于支持react操作DOM -->
  <script type="text/javascript" src="../js/react-dom.development.js"></script>
  <!-- 引入babel，用于将jsx转为js -->
  <script type="text/javascript" src="../js/babel.min.js"></script>
  <!-- 引入prop-types，用于对组件标签属性进行限制 -->
  <script type="text/javascript" src="../js/prop-types.js"></script>

  <script type="text/babel">
    // 1.创建组件
    class Demo extends React.Component {
      state = {
        isHot: true
      }

      // 展示左侧输入框的数据
      showInfo = () => {
        const {input1} = this
        alert(input1.value)
      }

      changeWeather = () => {
        const {isHot} = this.state
        this.setState({isHot: !isHot})
      }

      saveInput = (c) => {
        this.input1 = c
        console.log('@', c)
      }

      render() {
        const {isHot} = this.state
        return (
          <div>
            <h2>今天天气很{isHot ? '炎热' : '凉爽'}</h2>
            {/*<input ref={(c) => {this.input1 = c;console.log('@', c)}} type="text"/><br/><br/>*/}
            <input ref={this.saveInput} type="text"/><br/><br/>
            <button onClick={this.showInfo}>点我提示输入的数据</button>
            <button onClick={this.changeWeather}>点我切换天气</button>
          </div>
        )
      }
    }

    // 2.渲染组件到页面
    ReactDOM.render(<Demo />, document.getElementById('test1'))
  </script>
</body>
</html>
